This invention relates to landscape edging, specifically concrete, brick or wood landscape edgings comprised of block or post-like elements in side-by-side (not stacked) arrangement.
Heretofore, landscape edgings of this type required a substantial portion of each element to be burled so as to hold the element upright. Whereas this is less of a problem with very slender elements which can be pounded into the ground with a hammer, the more elegant, massive elements commonly preferred must be set into a deep trench and back-filled with earth to keep them upright. This is especially true when the landscape edging is intended to withhold substantial amounts of garden soil, since the weight of the soil tends to push the elements out of plumb. A related problem is alignment. A single block or post which is leaning is visually obvious among other adjacent elements which are not leaning. Yet another problem is roots or rocks, which may make trenching very difficult indeed.
In the southern U.S., where heavy rains and grass species that spread by roots rather than seeds are common, landscape edgings of this type are commonly used to raise the garden level so as to give garden plants good drainage, as well as to combat grass encroachment. Such edging structures in a state of disrepair are a very common sight, probably more so than edging structures with all the elements in plumb alignment, as they were originally.
A great many products are currently on the market which seek to address these problems. Stakes are supplied with some very short or light-duty edgings, but these are generally rather cheap and obviously only suited for decorative uses. The easier to solve alignment problem is generally dealt with by inconspicuously tying a number of elements together with wire or strips of metal or plastic. Unfortunately the entire group must still be installed in a sufficiently deep trench as to hold it plumb. Another approach is to provide each element (or group of connected elements) with tongue-and-groove joinery along the connective edges. Manufacturers of both scalloped concrete edging blocks and wooden edgings have used this technique. While this is helpful, it is no solution, as such edgings still lack tensile strength and still must be deeply inset in the ground.
Edgings of this type are also frequently constructed from short, site-cut vertically oriented lengths of landscaping timbers, railroad ties or other dimensioned lumber and may be "toe-nailed" together at the tops to help each stay in alignment.
The alignment problem, however, is just a symptom of the trenching and root problems since if each element were to be sufficiently ground-anchored it would not fall out of alignment in the first place. Most users who desire this style of landscape edging would, therefore, find a landscape edging which requires little or no trenching, can pass over troublesome roots or rocks, will stay in plumb alignment even when withholding garden soil and be easy to install extremely desirable.